- b.To begin, we must make certain that the
numerator and denominator are both com-
pletely factored and that all common terms are
canceled:
[xx+–3^5 – x]x–^1 3 = [xx+–3^5 – x(xx–– 3 3)]x–^1 3 =
(x– 3) = – (x^2 – 4x– 5) =
–(x–5)(x+ 1)
Determine the x-values that make this expres-
sion equal to zero or undefined.Then, we assess
the sign of the expression on the left side on
each subinterval formed using these values. To
this end, observe that these values are x= –1,
3, 5. Now, we form a number line, choose a
real number in each subinterval, and record
the sign of the expression above each:
Since the inequality does not include “equals,”
we would not include those values from the
number line that make the numerator equal to
zero. As such, we conclude that the solution set
is [–1, 3)∪(3, 5).
- d.Our first step is to make certain that the
numerator and denominator are both com-
pletely factored and that all common terms
are canceled:
2 xx+1– 2 x^1 –1+ = –
+ = =
= =
Now, the strategy is to determine the x-values
that make this expression equal to zero or
undefined. Then, we assess the sign of the
expression on the left side on each subinterval
formed using these values. To this end, observe
that these values are x= –^12 ,–^14 ,^12 , and 1. Next,
form a number line, choose a real number in
each subinterval, and record the sign of the
expression above each:
Since the inequality includes “equals,” we
include those values from the number line that
make the numerator equal to zero. The solution
set is (–^12 ,–^14 ]∪(^12 , 1].
- d.First, we must make certain that the numer-
ator and denominator are both completely fac-
tored and that all common terms are canceled,
as follows:
(^3 yy–+ 12 ) 2 – (y–^71 y)(–y^3 +1)+ =
yy++1 1 – (y–^71 y)(–y^3 +1)yy––1 1 + y+^5 1 =
=
=
=
= =
Now, the strategy is to determine the y-values
that make this expression equal to zero or
undefined. Then, we assess the sign of the
expression on the left side on each subinterval
formed using these values. To this end, observe
that these values are y = –4, –1, 1. Next, we
form a number line, choose a real number in
y+ 4
(y– 1)^2
(y+4)(y+ 1)
(y– 1)^2 (y+ 1)
y^2 + 5y+ 4
(y– 1)^2 (y+ 1)
^3 y^2 + 5y+ 2 – 7y^2 + 10y– 3 + 5y^2 – 10y+ 5
(y– 1)^2 (y+ 1)
^3 y^2 + 5y+ 2 – (7y^2 – 10y+ 3) + 5(y^2 – 2y+ 1)
(y– 1)^2 (y+ 1)
(3y+ 2)(y+ 1) – (7y–3)(y– 1) + 5(y–1)^2
(y– 1)^2 (y+1)
(y–1)^2
(y– 1)^2
^3 y+ 2
(y– 1)^2
^5
(y+ 1)
1
+ – + +–
-^121412
(4x+ 1)(x– 1)
(2x– 1)(2x+ 1)
^4 x^2 – 3x– 1
(2x– 1)(2x+ 1)
^2 x^2 – x– 2x– 1 + 2x^2
(2x– 1)(2x+ 1)
x(2x– 1) – 1(2x+ 1) + 2x^2
(2x– 1)(2x+ 1)
^2 x^2
4 x^2 – 1
^2 x+ 1
2 x+ 1
^1
2 x– 1
^2 x– 1
2 x– 1
x
2 x+ 1
^2 x^2
4 x^2 – 1
1 3 5
- –
x+ 5 – x^2 + 3x
x– 3
ANSWERS & EXPLANATIONS–